Exhaust-steam injector



June 19, 1928.

R. D. METcALl-E r-:r AL

- EXHAUST STEAM INJECTOR 1N VEN TORS A TTORNEY,

X36/,Miep .D /VErrALFE Jaw/Es C. Meren/ rf June 19,1928.` 1,674,443

-R. D. METCALFE ET AL EXHAUST STEAM INJECTOR Filed Aug. 12, 192e 2 sheets-sheet 2 l 'INVENToRs ./4/755 .C1 /yfrcALf-'s BY @fm ATTORNEY.

Patented .lune 19, 1928.

RICHARD DAVID METCALFE AND .TA1/res oaoxou METCALFE, or ROMILE, ENGDAni Marostica EXHAUST-STEAM INJ'EOTOR.

Application filed August 12, 1926, seriai No. 128,874, and in Germany August 24, 1925.

This invention relates to injectors which lication of our Re-issue Pate-nt No. 16,398

granted July 27, 1926, United States Patent No. 1,510,999. y

Our present invention comprises an improved arrangement of valve4 which automatically closes the exhaust steam inlet if the injector be Working with live steam throttled down to loW pressure and exhaust steam is not available, which prevents the How of exhaust steam to the injector when the latter is not desired to Work, and which ismainta'ined in an open or mid-position when it is desired to Work the injector with exhaust steam.

Referring toV the accompanying explana` Fig. 1 is a sectional elevation and Figure 2 a sectional plan view of an exhaust injector having our improved valve arrangement applied thereto.

Figure 3 is a sectionalplan view drawn to an enlarged scale of part of an exhaust inject-or showing a modified construction of valve. v

The same reference letters in the three vievvs indicate the same parts.

The construction of exhaust injector illustrated is similar to that in our prior application before referred to. a is the exhaust steam inlet, the supplementary live steam inlet through which the. live steam which assists in raising the delivery pressure of the injector enters thelatter. c is the inlet for live steam throttled down to a loW or to about atmospheric pressure for Working the injector when exhaust steam is not available. d is the Water inlet.

The exhaust valve e is carried b-y a stem f passing through guides at each end, the valve being adapted to seat on either of tWo seats g and 7L.

Vithin the cylinder i in the steamsupply litting at the entrance to the injectorl is a piston j, the latter being adapted to bear upon the end of the stem f in order yto prevent the exhaust valve e clos-ing on the seat h under the pressure of the exhaust steam entering at a and passing intothe injector. When the pistony is atthe end lofits operative stroke it abuts againstthe nut 7s' which prevents the passage or leakage of vrsteam along the piston. Steam is supplied to the cylinder z' from a control litting, not shown',

by way of the connection m, see Figure. 2.

The action of the valve e is as follows?-` Assuming that the injector is vtofbe Worked with exhaust steam from the passagev @the operator admits "live steam to the cylinder z' so that the piston j is movedjagainst a' seating on the nut 71; to the positiony shown. The valve c is forced oif the seat into the position shown byl the exhaust vsteam Aso 4that such steam can pass into the injector.

If exhaust steam is present. at ,d and theiny y ject-or is not required to Work, the steam is exhausted from the cylinder z' bythe control. fitting, not shovvn, and the valve is forced by the exhaust steam on to the seat preventingV the steam passing throughV the injector and out at the' overflow passages.

If the injector, is toy be Worked rle'yv'live steam throttled down to a lo'vv or about atmospheric pressure-because exhaust steam is not available, the valve e Will be forced onto its seat g by the steam pressure Within the injector, so preventing any escape of steam from the injector through the passage a.

In the arrangement shown vin Figure 3, a fixed guide stem 0 is-supported from the valve seat g and the valve e has a slee-veabuts for the purpose before described. Whilst the part has been shown as a piston a valve which closes vagainst the seat like, extension f against which the piston j on the nut la When steam is admitted to z' passage, a valve located in said passage betvveen said seats and adapted to engage one or the other thereof to close the passage,

said valve being free at `all times to be shiftl2. In an ejector having a passage connect-v ing exhaust and live steamV inlets, a pair of spaced valve seats each encompassing said passage intermediate said inlets, a valve located between and adapted to engage one or the other of said seats, said valve being constructed and arranged to be automatically shifted toward one of said seats by exhaust steam pressure and toward the other of said seats by live steam pressure, and means to hold said valve in an intermediate position between said seats .against exhaust steam pressure under predetermined conditions.

3. In an injector having a passage connecting exhaust and live steam inlets, a pair of valve seats each encompassing said passage intermediate said inlets, a valve mounted between said yseats and freely movable to engage. one or the other of said seats under the influence of exhaust or live steam pres sure respectively, and manually controlled fluid pressure actuated means engaging said valve to permit its freetravel only between one of said seats and a' point intermediate said seats.

4f. In anrinjector having a passage con'- necting exhaust and live steamV inlets, a pair of valve seats each encompassing said passage intermediate said inlets, a valve slidably mounted between said seats and freely movable to engage one or the other of said seats Vunder the influence of exhaust or live steam pressure, respectively and a fluid pressure actuated piston operative under pre'- determined 'conditions to engage' said valve to permit its free travel only between one of 5. In an injector having a passage con.-v

necting exhaust and livesteam inlets, a pair of aligned valve seats each encompassing` said passage Vintermediate said inlets, a cylinder located longitudinally of the central axis through said seats, bearing members located in alignment with said cylinder, a valve stem slidably mounted in said bearing members and extending into said cylinder, a valve disc mounted on said stem intermediate said seats and having oppositely disposed faces adapted to engage one or the other of said seats to close said passage,l and a freely movable fluid pressure actuated piston located in said cylinder and adapted to abut against said stem to limit its travel.

6. In an injector having a passage con'- necting exhaust and live steam inlets, a pair of aligned valve seats each. encompassing said passage Vintermediata-v said inlets, a cylinder located longitudinally of .the central axis throutfih'said seats, bearing members located in alignment `with said cylinder, a valve stem slidably mounted in said bearing members and extending into said cylinder, a valve disc mounted on said stem intermediate said seats having oppositely disposed faces adapted to engage one or the other' of said seats, a freely movable piston located in said cylinder, means for admitting fluid under pressure to said cylinder to force sai-d piston to one end of the cylinder and thereby limit the travel of said valve stem, and means forn'iing a iuid-tight ljoint between said piston and the end of said cylinder to prevent the leakage of fluid from the latter.

RICHARD DAviD MnTc'ALrE. JAMES cRoxoN METCALFE. 

